Anura Unit

The Anura Unit was formed by Toad Man and his prototypical brother, Frog Man. Hoping to vie for their own stint of world domination (presumably after a flaw in their programming code caused by some sort of physical damage incurred upon them somehow), they would eventually come across Dr. Kojiro'sPoison Man, and after what may have been reprogramming to make Poison Man more "free-willed" himself, the three would go on to hire freelance French scientist named Dr. Grenouille to construct another five robot masters to fill out their ranks.

Initially, Dr. Grenouille took the order to "make Robot Masters like us" quite literally, and she therefore designed both Gold Man and Hylid Man directly after Frog & Toad's body styles. However, afterwards she realized they did not need precision in design and the next four were more unique in physiology.

No longer declaring allegience to their original masters (although Dr. Grenouille was considered highly by their order), they served no one but themselves and would declare war on the world. This would initially go well for them, they would quickly be stopped by Mega Man.

After the initial Anura Unit's defeat, they would regroup and have Dr. Grenouille construct a large number of new members for a second, more vengefully-driven attempt at world domination. Because of their desire to finish the army as fast as possible, most were allowed to be based upon the blueprints of Frog Man and Toad Man, although some unique RMs were peppered between the numerous "shell clones" when time was available to create one.